Carburetor



Patented Aug. 2a, 193s UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to a fuel carburetor for an internal combustionengine.

It is an object of this invention to produce a carburetor for aninternal combustion engine which will produce a highly atomized mixtureof fuel and air regardlessof whether the fuel is gasoline or the highboiling distillates such as the numerous fuel oils which are burned bothin domestic as well as in industrial heating plants including such fuelsas kerosene and fuel oils No. 1, 2 and 3 such as are commonly used indomestic and industrial oil burners.

It is also an object of this invention to produce a fuel carburetor foran internal combustion engine which is highly efficient in producing anatomized mixture of fuel and air thereby effecting economies in theoperation of the engine as well as a smoother running of the engine.

Another object of this invention is the production of a carburetor whichis simple in structure and which will produce a uniform mixture of fueland air at all speeds of the engine.

This invention also contemplates a carburetor that will produce auniform mixture of fuel and air regardless of whether the carburetor ispositioned right side up as occurs when the injector is used for anautomobile engine and the vehicle is traveling on a level road, orupside down as would often occur when the carburetor is used for anaeroplane engine, or in some intermediate angular position as very oftenoccurs when the automobile is driving along a road with a roundedsurface, uphill, or around a curve in a road which is banked.

In the drawing: v

Fig. 1 is a vertical section through the carburetor showing the injectorin idling position in the full lines and in wide open position in thedotted lines.

Fig. 2 is a section along the line 2-2 of Fig. 1.

Fig. 3 is an enlarged fragmentary detail of the needle valve and fuelinlet.

Fig. 4 is a detail showing of a modified form of the connection betweenthe air valve and counterbalancing lever.

Referring more particularly to the drawing it will be seen that thecarburetor comprises the outer shell portions I and 2 which are securedtogether by any suitable means such as the screws 3. The shell portion Iencompasses the mixing chamber 4 where the fuel is atomized and mixedwith air. The shell portion I is provided with a suitable flange 5 whichmay be bolted or otherwise secured to the intake manifold of theinternal combustion engine with which this carburetor is used. The shell2 is open at its upper end as at 6 to provide an opening through whichthe air passes into the air intake passageway 9 encompassed by the shell2. The upper end 6 of the shell 2 may be provided with any suitableconventional air cleaner and silencer.

The air inlet is provided with the usual butterfly valve 1 which ispivoted to swing on the pin 8. The butterfly valve l may be manuallycontrolled by a hand throttle or by a foot control in the form of aconventional accelerator pedal. Any suitable fuel pump may be used forsupplying the carburetor with fuel. To this end the fuel line I isconnected directly to the fuel pump so that the fuel is supplied to thecarburetor under positive pressure. The end of the fuel line I0 (Fig. 3)is provided with a nipple II. Thenipple II has a fuel inlet orifice I2which s controlled by the needle valve I3.

It is lproposed to heat the fuel preparatory to injecting it into themixing chamber. Therefore the fuel line I0 and nipple I I are surroundedby a tubular casing I4 which encompasses a heating chamber I5. A pipeline I6 is threaded into the casing I4 for supplying heat to the chamberI5. The heat. units which are supplied to the chamber I may take theform of hot air or steam but preferably the line I6 is connected withthe exhaust manifold so that a small supply of exhaust gases underpressure is conducted by the line I6 into chamber I5, thence past thefuel inlet orifice I2 and through the orifice I1 which is alsocontrolled by the needle valve I3. The exhaust gases are preferably usedas a source for preheating the fuel because of their high Water content.The exhaust gases in passing by the orice I2 and nipple II have anaspirating effect on the fuel supplied to the nipple Il by the fuel lineI0. However, the positive pressure of the fuel pump is relied uponprimarily for injecting the fuel into the mixing chamber 4.

In view of the fact that this invention contemplates a carburetor whichwill produce a uniform mixture of air and fuel at all motor speeds, tothis end the injection of fuel and the admission of air into the mixingchamber 4 are at all times coordinated so that the mixture will remainuniform. The mixture of gasoline and air may be according to any properratio such as fifteen pounds of air to one pound of gasoline and thisratio, of course, will be varied depending upon the type of fuel used.To this end the air intake passageway 9 is provided with a control valvewhich takes the form of a conical valve I8 mounted on the stem I9. Thestem ciprocably mounted in the cylinder 20 provided with a breathingport 2|. 'I'he needle valve I3 is provided with a stem 22 which isreciprocably mounted in the guideway 23 provided by the spider 24. 'I'heupper end of the stem 22 is also guided as at 25 in the closure cap `26which is threaded into the carburetor shell as at 21. 'I'he stem of theneedle valve is also provided with a shoulder 28 which is seated uponthe bifurcated I9 is reend 29 of lever @d which is pivoted within thecarburetor` shell upon the pin 3G. The stem I9 of the valve i8 isprovided with a shoulder which is seatedupon the other bifurcated end 33of the lever Threaded over the upper end of the stem 22 and positionedbetween the shoulder 2S and the closure member 26 is a; coil spring 963.The tension of this coil spring l3Il is gauged so that the valve I8 isheld closed when the engine is not running but will open as soon assuflicient vacuum is created in the mixing chamber 4 to draw air throughthe intake passageway 9. 'I'he coil spring 34 is tensioned relative tothe weight of the needle valve stem 22 and valve I8 and stem I9 to makethe valve I8 highly responsive or sensitive to the kinetic energy orforce of the air passing through the intake passageway 9 into the mixingchamber 4. 'I'he buttery valve 1 controls the amount of the air which ispermitted to pass through the intake passageway 9 and therefore theamount of the displacement ofthe valve` I8 corresponds to the amountthatthe butterfly valve 1 has opened. As shown in the full lines thebutterfly valve 1 and valve `I8 are approximately in idling position.The dotted line showing of the valve I8 shows the position of the valvewhen the butterfly valve 1 is wide open. l

There are times, such as in the summer time or in tropical regions,where due to the heat the density of the air is reduced sufficiently torequire the admission of an additional amount of air in the mixingchamber 4. To this end the carburetor is provided with a bypasspassageway 35 which permits air to pass around the valve I8 directlyfrom the intake passageway 9 into the mixing chamber 4. The bypasspassageway 35 is controlled by a butterfly valve 36. 'I'his butterflyvalve 36 is controlled by a thermostatic bimetal element 38. Normallythe valve 36 will remain closed thus shutting oif the bypass passageway35. However, when the temperature of the air under the hood passes apredetermined point the bimetal element 38 will respond to thispredetermining temperature and begin to open the valve 36. Thethermostatic bimetal element 38 will be fabricated and regulated so thatupon additional increase in temperature the valve 36 will open furthercorresponding to the increase in temperature. The thermostatic element38 will start opening the valve 36 at approximately 60 F. under hoodtemperature and will completely open the valve at about 200 F. underhood temperature. 'This temperature range in which the thermostaticbimetal element 38 begins to open and completely opens or begins toclose and completely closes the valve 36 will vary with the fuel used.

An additional by-passageway 39 is provided around the valve I8. Thispassageway 39 is provided with a butterfly valve 40 manually controlledby the rod 4I which leads to the instrument board of the automotivevehicle. This manually controlled by-passageway 39 will normally beclosed but will be opened whenever the carburetor or engine areoperating in high altitudes where the rariflcation or lower densitynecessitates the admission of additional quantities of air into themixing chamber 4 to maintain the desired uniformity of mixture ofatomized fuel and air.

As shown in Fig. 4, the valve stem I9 is provided with a slot 45 whichreceives the disc shaped end v46 of the lever 30. The valve I8 isdrilled and tapped to receive the set screw 41 and the aiaaove lock nut38. The lower end of the set screw 41 engages the disc end i6 of thelever 88 to provide an adjustable connection between the lever @d andthe valve stem i9. This connection loetween the lever 3@ and valve stemi9 is positive so that the valve B9 must necessarily move back and forthwith the lever arm 39.

In operation the carburetor functions as follows: When the engine is notrunning the valve I ii closes the air inlet port i2 and the needle valveI3 closes the fuel inlet orice I2 and oriflee I1. As soon as the motoris turned over a vacuum is created in the chamber i which causes thevalve I8 to open which in turn operating through the lever 39 raises theneedle valve AI3 to open ports I2 and I1. The valve I8 now acts as avane and the kinetic energy of the air flowing by valve I8 holds itopen. As soon as ports I2 and I1 are opened, fuel is forced through theorice I2 by the fuel pump and strikes against the conical portion 52 atthe lower end of the needle valve stem 22 and at the same time exhaustgases pass upwardly into the chamber 4 about the nlpple II through theorifice I1. This atomizes the fuel. A downward ilow'of air through theair passageway 9 and port 42 strikes the fuel thus intimately mixing thefuel with air before it passes through the outlet 43into the lintakemanifold of the engine. As soon as the engine starts running thisoperation of the carburetor continues. However, hot exhaust gases willnow be passed through the exhaust line I6 into the chamber I6 where thefuel will be preheated before being ejected through the orifice I2. Atthe same time the accelerated flow of exhaust gases through the orificeI1 will atomize the fuel and assist in its mixture in this highlyatomized state with the air passing through the intake opening 42 intothe mixing chamber 4 preparatory to passing through the outlet 43 intothe intake manifold of the motor.

It will be\ noted that the needle valve I3 is tapered thus the higherthe needle valve I3 is raised, as viewed in Figs. 1 and 3, the less thefuel inlet orifice I2 and oriflce I1 are obstructed thus permitting agreater amount of fuel to be ejected through orifice I2 and a greateramount of exhaust gases and fuel to be ejected through orice I 1. Inother words, the valve I3 meters the fuel as it is ejected into mixingchamber 4. The taper of the needle valve I3 and size of the orifices I2and I1 are fabricated and gauged so that in any position of the valve I8the corresponding position of the valve I3 will be such that the ratioof air admitted through the intake opening 42 and the fuel ejectedthrough the orifices I2 and I1 into the mixing chamber will remainapproximately constant thus insuring a uniform mixture of fuel and airat all operating speeds of the engine.

It is obvious from the above description that the further the butterflyvalve 1 is open the further the valve I8 will open and in turn thefurther the needle valve I3 will be opened. It will be noted that thebutterfly valve 1 is positioned above or ahead of the mixing chamber 4and fuel inlet orifice I2 and I1. This positioning of the butterflyvalve ahead of the mixing charnber is important because after the fuelis once atomized and mixed with the air in the mixing chamber 4 it ispassed in this highly atomized mixed state directly into the intakemanifold of the engine. This free passageway between the mixing chamber4 and the intake manifold of the engine insures that the mixture will befed into 75 the cylinders in its highly atomized state because anyobstruction such as a butterfly valve between the mixing chamber and theintake manifold would cause the atomized fuel to condense and therebywould cause a certain amount of raw and unmixed fuel to pass through themanifold into the cylinders. The tubular casing I4 is preferablycircular in cross section so that it presents what may be termed astream line surface to the flow of high atomized mixture of fuel and airand therefore does not cause the fuel to condense on the surface of thetubular casing I4.

When the needle valve I3 completely closes fuel inlet orifice l2 -asoccurs when the butterfly valve 8 completely closes the air inlet 9,then as long as the motor continues to turn over, the fuel pump will, ofcourse, continue to pump fuel but the fuel will be by-passed from thepressure or output side of the pump back around to the intake side ofthe pump in the well-known and conventional manner.

I claim:

1. A carburetor for atomizing fuel and mixing the same with airpreparatory to being burned in an internal combustion engine comprisingin combination a casing encompassing a mixing chamber having an airinlet and an outlet for the mixture of air and fuel, a valve forcontrolling the air inlet, means responsive to the flow of air passingthrough the air inlet, a fuel inlet for supplying fuel to the saidmixing chamber where the fuel is atomized and mixed with the air, achamber surrounding the fuel inlet and provided with an outlet spacedfrom the fuel inlet, means for supplying a gas to the last mentionedchamber surrounding the fuel inlet, the said fuel and gas passingthrough the opening in the last mentioned chamber into the mixingchamber and a needle valve for controlling both the fuel inlet and thegas outlet, and means interconnecting the fuel inlet valve and the airresponsive means whereby the admission of fuel and air into the mixingchamber is coordinated and the mixture ratio of air to fuel ismaintained approximately the same at all times during the operation ofthe carburetor.

2. A carburetor for atomizing fuel by mixing the same with airpreparatory to being burned in an internal combustion engine comprisingin combination, a casing encompassing a mixing chamber having an airinlet and an outlet for the mixture of air and fuel, a manually operatedvalve for controlling the flow of air through the air inlet, an uprightconical valve reciprocably mounted in and responsive to the ilow of airpassing through said inlet and arranged to open in a downstreamdirection to progressively increase the effective unobstructed area ofsaid inlet port, a fuel inlet for supplying fuel to the said mixingchamber, a tapered metering valve for said fuel inlet arranged to opento progressively increase the effective unobstructed area of said fuelinlet, said tapered metering valve having an inverted conical portionexposed directly to the air in the said mixing chamber, a chambersurrounding the fuel inlet in spaced relation therewith and providedwith an outlet into the said mixing chamber, means for supplying gas tothe last mentioned chamber. said last mentioned chamber directing a flowof gas by the fuel inlet before the fuel and gas passes out of the saidoutlet into the mixing chamber, the

said fuel and gas upon passing through the said l outlet impingingagainst the inverted conical portion of the tapered metering valve aa itenters the mixing chamber, means interconnecting said conical andtapered valves for translating the opening movement of the conical valveto the tapered valve to simultaneously and correspondingly open the saidtapered valve, the taper of the said metering valve being gaugedrelative to the taper of said conical valve whereby as the conical valveprogressively opens responsive to an increase in volume of air flowingthrough said air inlet the tapered metering valve correspondinglyprogressively opens to admit a corresponding increase in the amount offuel admitted to said mixing chamber to thereby maintain said fuel toair ratio in said mixing chamber approximately constant.

3. A carburetor for atomizing fuel and mixing the same with airpreparatory to being burned in an internal combustion engine comprisingin combination a casing encompassing a mixing chamber having an airinlet and an outlet for the mixture of air and fuel, a valve forcontrolling the flow of air through the air inlet, means responsive tothe flow of air passing through the air inlet, a fuel inlet forsupplying fuel to the said mixing chamber where the fuel is atomized andmixed with the air, a chamber adapted to receive gas surrounding thefuel inlet and provided with a gas outlet spaced from the fuel inlet.means for supplying a gas to the last mentioned chamber surrounding thefuel inlet. a metering valve for controlling both the fuel inlet and thegas outlet and provided with an inverted conical portion positionedwithin and exposed directly to the air within the mixing chamber againstwhich the said fuel and gas simultaneously impinges upon entering themixing chamber, and means interconnecting the fuel inlet and the airresponsive means whereby the admission of fuel and air into the mixingchamber is coordinated and the mixture ratio of air to fuel ismaintained approximately the same at all times during the operation ofthe carburetor.

4. A carburetor for atomizing fuel and mixing the same with airpreparatory to being burned in an internal combustion engine comprisingin combination a casing encompassing a mixing chamber having an airinlet and an outlet for the mixture of air and fuel, a valve forcontrolling the flow of air through the air inlet, means responsive tothe flow of air passing through the air inlet, a fuel inlet forsupplying fuel to the said mixing chamber where the fuel is atomized andmixed with the air, a chamber adapted to receive gas surrounding thefuel inlet and provided with a gas outlet spaced from the fuel inlet,means for supplying a gas to the last mentioned chamber surrounding thefuel inlet, a tapered metering valve for controlling both the fuel inletand the gas outlet and provided with an inverted conical portionpositioned within and exposed directly to the air within the mixingchamber against which the said fuel and gas simultaneously impinges uponentering the mixing chamber, the said inverted conical portion of thesaid tapered valve being in axial alignment with the said gas outlet andfuel inlet, and means interconnecting the fuel inlet and the airresponsive means whereby the admission of fuel and air into the mixingchamber is coordinated and the mixture ratio of air to fuel ismaintained approximately the same at all times during the operation ofthe carburetor.

BAILEY P. pawns. u

